This application seeks to follow the participants in Study of Novel Approaches to Weight Gain Prevention (SNAP) (Grant #U01-HL090864), a randomized clinical trial that has successfully reduced weight gain in young adults through 3 years. SNAP is the first weight gain prevention trial to show positive effects over an extended time period in this age group. The SNAP-Extension (SNAP-E) will cost-effectively determine whether the effects of the intervention can be maintained over 3 additional years (through a total of 6 years). Young adults, ages 20-35, gain on average 2 pounds per year, increasing their risk of developing obesity and obesity related co-morbidities. Previous efforts to prevent this weight gain have had limited success. SNAP is a randomized controlled clinical trial involving 599 participants, age 18-35 with a BMI of 23- 30, comparing weight changes over an average follow-up of 3 years in a control group and two innovative interventions. Both interventions are based on a self-regulation model, involving frequent self-weighing and changes in eating and activity if weight gain occurs. However, one intervention focuses on making small consistent changes in eating and exercise behavior to prevent weight gain; the other emphasizes periodic larger changes in eating and exercise, with a goal of producing a buffer against anticipated weight gains. SNAP has had excellent retention to date and has shown that both interventions significantly reduced weight gain relative to control through 3 years. Although weight changes in the two interventions do not differ from each other at 3 years, they have had very different weight change trajectories, raising questions about long- term efficacy. Continuing to follow these participants is critical to determine whether the skills imparted during these interventions and the resulting beneficial effects on weight gain are maintained longer term and whether there are differences in outcomes for large and small change approaches. In SNAP-E we will provide minimal intervention for the Small and Large Change groups using remote technology and will follow all participants at 6 month intervals using Smart Scales and on-line questionnaires. There will be one final clinic assessment at Year 6, with measures of body composition, cardiovascular disease (CVD) risk factors, dietary intake and objective assessment of physical activity, all implemented using procedures that were used throughout SNAP. The primary hypothesis of SNAP-E is that the magnitude of weight gain from baseline to 6 years will differ among the three arms. Secondary hypotheses compare the groups on dichotomous measures of weight gain, on CVD risk factors, and on weight control behaviors. Preventing weight gain may be a more effective public health approach than treating obesity. SNAP is the first study to show long-term benefits of an intervention on weight gain in young adults. Continuing to follow these participants in SNAP-E provides a cost-effective and unique opportunity to answer important questions about weight gain prevention.